The present invention relates to motion detection. More specifically, the present invention relates to methods and apparatus for real-time motion direction detection.
The inventors of the present invention have utilized gyroscopes to help determine how a hand-held device is moved in space. Using physical gyroscopes, the inventors have determined that they provide accurate x, y and z rotation (panning direction) data, however the inventors have also determined that using physical gyroscopes have drawbacks. One drawback is that gyroscopes are relatively expensive to manufacture because of physics of such small scale devices. Another drawback is that they consume a relatively high amounts of power, which may be in the order of miliwatts. This high power consumption greatly limits use of physical gyroscopes in low power applications, such as in handheld devices, wearable devices, and the like.
The inventors have also experimented with virtual gyroscopes based upon accelerometer and magnetometer data to estimate motion data for the device. However the inventors have determined drawbacks with such virtual gyroscopes include that cross-axis artifacts are often returned as a result of the computations. As an example, a panning motion within an x-y plane, may be computed to, incorrectly, have some motion in the z-direction.
In light of the above, what is desired are improved methods and apparatus for real-time motion direction detection with reduced drawbacks.